<html>
  <head>
    <meta charset="utf-8">
  </head>

  <body>
    <h1>Testing...</h1>

    <script>
      (() => {
        'use strict';
        document.addEventListener('DOMContentLoaded', () => {
          console.info('DOMContentLoaded');
        });

        document.onreadystatechange = () => {
          console.info('readystatechange = ' + document.readyState);
        };

        window.onload = () => {
          console.info('window.onload');
        };

      })();
    </script>
  </body>
</html>
